In Dual-Subscriber Identity Module (SIM), Dual-Active (DSDA) mobile devices supporting Wideband Code Division Multiple Access (WCDMA) and Global System for Mobile communications (GSM) radio access technologies, Opportunistic Mobile Receive Diversity (OMRD) provides WCDMA receive diversity only when GSM is in sleep mode. When GSM is in traffic, i.e., when GSM is using its receiver during a voice or data call, making the GSM receiver chain unavailable to WCDMA so receive diversity cannot be accomplished for WCDMA.
GSM, however, has a low receive duty cycle in traffic so for a large portion of the time when GSM is in traffic GSM is not actively using its receiver chain. During those portions of time, the GSM receiver chain may be used by WCDMA. Conventional designs for OMRD use diversity/non-diversity mode switching involving a large amount of software overhead making conventional OMRD impractical for frequent switching from the GSM receive duty cycle.